Effective electrochemical water oxidation to H2O2 based on a bimetallic Fe/Co metal–organic framework

Abstract

Rationally designing high-efficiency catalysts for electrochemical two-electron water oxidation reaction (2e⁻ WOR) to produce hydrogen peroxide (H₂O₂) is extremely important, while designing bimetallic metal–organic frameworks (MOFs) is of great significance for effective 2e⁻ WOR. Herein, MIL-53(Fe) and different proportions of Co-doped MIL-53(Fe) were prepared by a hydrothermal method. The structural characterization and elemental analysis showed that the Co ions were successfully doped into MIL-53(Fe) to form a MIL-53(Fe/Co) bimetallic MOF, and the morphology of MIL-53(Fe/Co) became more regular after Co doping. We found that the optimized MIL-53(Fe/Co) exhibits remarkable 2e⁻ WOR performance, which gave an overpotential of 150 mV at 1 mA cm⁻². The overpotential of MIL-53(Fe/Co) was approximately 220 mV (at 1 mA cm⁻²) lower than that of MIL-53(Fe), which may be attributed to the change of microstructure of MIL-53(Fe) after Co doping and the synergistic effect between Fe/Co. Our work introduces a strategy for designing bimetallic MOF-based electrocatalysts, opening up new possibilities for efficient 2e⁻ WOR systems.